Transfer mechanism for horizontal redraw presses



Dec, 27, 1955 .1. s. BURTON 72,338

TRANSFER MECHANISM FOR HORIZONTAL REDRW PRESSES Filed Feb. l,- 1952 4 Sheets-me?. 2

.INI/EN TOR. MESSE B. BUT/V ,4 Www/E Y J. B. BURTON 2,728,318 TRANSFER MECHANISM FOR HORIZONTAL REDRAW PRESSES Dec. 27, 1955 4 Sheets-Sheet 5 INVENTOR.

JESSE 5. EUR TON BY )9v-ORNE Y Filed Feb. l, 1952 J. B. BURTON 2,728,318

TRANSFER MECHANISM FOR HORIZONTAL REDRAW PRESSES Dec. 27, 1955 4 Sheets-Sheet 4 Filed Feb. l, 1952 IN V EN TOR. JESSE B. BURTON BY A7Tof? NE Y TRANSFER MECHANISM FOR HORIZONTAL REDRAW PRESSES Jesse B. Burton, Waterbury, Conn., assignor to The Waterbury Farrel Foundry & Machine Company, Inc., Waterbury, Conn., a corporation of Connecticut Application February 1, 1952, Serial No. 269,407 2 Claims. (Cl. 113-113) This invention relates to shell drawing presses, and more particularly to a multiple punch and die horizontal redraw press in which the cooperating punches and dies act in sequence, starting with a preformed cup taken from a reciprocating feed slide, to form a completed shell in successive steps-the product drawn by one punch and die being automatically transferred to the next succeeding station.

The invention disclosed in the present application is an improvement over the Patent No. 1,982,460, dated November 27, 1934, for Transfer Mechanism, issued to Richard Lester Wilcox; and the Patent No. 2,183,287, dated December l2, 1939, for Horizontal Redraw Press, issued to Zenas P. Candee.

One object of the present invention is to provide an improved redraw press of the above nature in which successively longer products are produced at the series of stations.

Another object is to provide an improved redraw press of the above nature in which all of the punches are carried by a single reciprocating gate member.

Still another object is to provide an improved redraw press of the above nature having a rocking cross bar whereby the shells may be automatically and eficiently transferred from station to station by a parallel motion.

A further object is to provide an improved redraw press of the above nature having a plurality of pairs of cooperating resilient transfer lingers, which will eliminate the use of springs in the transfer mechanism, thus producing a simplied construction with a minimum number of parts.

A further object is to provide a transfer mechanism of the above nature in which the feed slide is provided with a dwell at the end of its movement, so as to permitA the transfer fingers to travel almost straight down over the cups and shells and lift the same vertically at the beginning of each transfer cycle.

A further object is to provide a redraw press ofthe above nature which will be relatively simple in construction, inexpensive to manufacture, easy to manipulate, compact, and Very efficient and durable in use.

With these and other objects in view there have been illustrated on the accompanying drawings two forms in which the invention may conveniently be embodied in practice.

in the drawings:

Fig. l is a side view, partly in section, of the redraw press showing the transfer mechanism at the start of a transfer cycle, with the feed slide ready to receive a cup from the feed channel.

Fig. 2 is a similar side view, with the parts as they appear at the mid-point of the transfer cycle.

Fig. 3 is a view similar to Figs. 1 and 2, showing the first pair of transfer fingers as they appear when picking up a cup from the feed slide, during the dwell period.

Fig. 4 is an end view of the same, looking from the right ofFig. 3. f ff Fig. 5 is a top view, partly in section, of the improved nited. States Pateit zontal pivot stud 17 secured v 19 is adapted to engage a shoulder 20 formed transfer mechanism with parts shown in the same position as in Fig. 3-the punches and dies and transfer fingers being omitted from all except the second station, for clearness.

Fig. 6 is a fragmentary view, similar to Fig. 5, of a modified form of mechanism for driving the feed slide, in which an extension of the transfer cross bar is connected with a shorter feed slide-operating link.

Fig. 7 is a fragmentary side View of the same.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numeral 10 (Fig. 3) indicates the bottom frame of the redraw press, which is connected to a bracket 11 by means of bolts 12, 13, and locating dowel pins 14, 15, for supporting the transfer and feed mechanisms to be hereinafter described.

The bracket 11 is provided with an upwardly extending triangular ear 16, within which is mounted a horiby means of a nut 17a to the 19 of a rocker lever 18. The arm near the outer end of a hollow feed slide 21 for forcing said slide outwardly against a coiled compression spring 22a, preferably formed of music wire.

The slide 21 embraces a vertical stop stud 22 preferably having a square head 23, said stud being rigidly mounted in a circular aperture 23a formed in the bracket 1l. The spring 22a is confined within the hollow slide 21 between the stud 22 and a forward shoulder 22b at the outer end of the feed pocket 26 of said slide 21.

Provision is also made of a horizontal headed adjusting screw 24 mounted in the end of the slide 21. Top guide caps 25, 25a are secured upon the ends of the bracket 11 to maintain said slide in operating position.

In order to feed a series of preformed cups C successively into`the press, which cups are successively drawn into shells S by the horizontal punches P and the stationary dies D, provision is made of a cup-shaped pocket 26 located in the inner end of the feed slide 21, said pocket being located underneath and adapted to move into alignment with the lower end of an S-shaped cupfeed channel 27 formed in a chute bracket 28 secured to a top bracket 37 of the machine as by screws 28a.

ice

lower curved arm Transfer mechanism inner end of the link 30 is connected to a stud 32 extending laterally from a crank arm 33, rigidly connected to a horizontal crank shaft 34, upon which is rigidly mounted a pinion 35, adapted to be reciprocated by a rack 36, by means of drive mechanism to be hereinafter described.

A similar crank shaft 34a, crank arm 33a, stud 32a, and pinion 35a are provided at the inner end of the transfer mechanism, said pinion 35a also being engaged with the rack 36.

The rack 36 is slidably mounted within a slot formed in the top bracket member 37 and said rack has an extension 38 pivotally secured by means of a stud 38u to a drive slide bar 39, which in turn is provided with a stud 39a carrying a roller 40, which is in engagement with a power driven cam 41 (see Fig. 5) serving to reciprocate said slide bar 39 and said rack 3 Provision is also made of a transfer cross bar 42 connected to the studs 32, 32a on the crank arms 33, 33a. The cross bar 42 carries a plurality of pairs of resilient, parallel, vertical opposed transfer fingers 43,' i4-said pairs of fingers being secured tothe cross bar 42 by means of attaching screws 4S (Figs. 2 and 5), which are surrounded by clamping blocks 46.

Each pair of the transfer fingers 43, 44 is provided with cooperating inwardly offset out-turned lower ends 47, 4S which have inwardly concave recesses 49, S0 for permitting said fingers to either snap-down upon or snap-up from the shells S during the transfer of said shells from station to station of the machine.

Provision is also made of a stripper bar 51 (Fig. 5), located in front of the cross bar 42, and to which are connected a plurality of stripper collars 53 retained in place upon the stripper bar 51 by means of key yokes 52.

By means of this construction, it will be clear that the shells S at each station will be automatically stripped from the punches P at the end of each drawing operation.

Provision is also made of a series of knock-out rods 54 which are adapted to eject the shells from the dies D after each drawing by the punches P, from which they are then stripped, so as to permit them to be transferred from each station successively to the next station by the transfer mechanism described above.

At the top of the transfer mechanism, provision is made of a pair of vertical apertured arms 63, 64 (as clearly shown in Fig. 5) by means of which said mechanism may be supported upon the base of the redraw press as by bolts (not shown).

Operation ln the operation of the present invention, a series of preformed metal cups C will be fed successively from a hopper, or any other source of supply (not shown) into the top of the channel 27 of the chute 28. The cups C will drop downwardly by the action of gravity and one of said cups will be separately received in the socket 26 at the inner end of the feed slide 21 at each stroke thereof as shown in Fig. l. The feed slide 21 will thereafter be moved from the position shown in Fig. l to the position shown in Fig. 3. While the punches P remain in retracted position, during a dwell in the drawing cycle, the drive cam 41 will force the slide bar 39 to reciprocate the rack 36, connected thereto, so as to cause the pairs of transfer fingers 43, 44 to move downwardly over the shells at the respective stations. During this operation, the tips 47, 48 of the resilient fingers 43, 44 will engage over the shells S, while they are still supported by the punches P, with a snap action. The punches P will then be withdrawn through the stripper bar 51, leaving the shells S securely held in the resilient transfer fingers 43, 44.

The crank arms 33, 33a will then be rocked to cause the transfer tingers 43, 44 to swing in a semi-circular arc with a parallel motion while constantly remaining vertical, and carrying the shells S into alignment with the punches and dies at the next succeeding station Where said shells will be deposited before the start of the succeeding stroke of the punches.

As will be noted by reference to Figs. l and 3 of the drawing, the products S, while they are being moved from one station to another by the transfer mechanism, will swing through an arc of somewhat more than 180, as indicated by the curved arrow on Fig. 3, thus obtaining the advantage of a substantially vertical movement of the lingers 43, 44 at each station. This will cause the fingers to spring-snap over the products during their downward movement, and spring-snap away from the same during their upward movement. Also, the action of the mechanism will be so timed that the gripping transfer fingers 43, 44 will not be withdrawn from the shells S until a short time after the punches have entered said shells on the next succeeding punching stroke, but before any movement of the shells has taken place.

When the next stroke of the punches P occurs, the product S will be engaged thereby and forced by means of said punches, through the dies D, the proper distances.

The closed end of each product will be carried by the punches a suflicient amount through and beyond the respective dies to give the required draw to said productthe dies of course, being staggered to permit the products to be drawn to the desired lengths.

The knockout rods 54 will then force the shells out of the dies horizontally, and the shells will be grasped by the pairs of transfer fingers 43, 44. The open ends of the shells S will then engage their respective stripper collars 53, and continued movement of the punch-carrying gate (not shown) will strip all of the shells S from the punches P, so that said shells may be transferred to the next stations.

While the present invention has been described for use on a horizontal redraw press, it will be understood that it is within the scope thereof to employ the same construction for a redraw press in which the punches move vertically or in any other direction.

One advantage of the present invention is that, if desired, the drive slide bar may be driven from its inner end as well as from the'outer end thereof, as shown herein.

A further advantage is that the cup feed slide is driven from the transfer cross bar by means of a link` and lever mechanism, thereby avoiding the use of the complicated and expensive cam drives employed in the above-mentioned Wilcox and Candee patents.

An important feature of the present invention is that a lost motion occurs at the extreme inward motion of the feed slide 21. This occurs after the screw 24 on the end of the slide strikes the square head 3 of the stationary stud 22 in the frame 10.

The lower arm 19 of the lever 18 is thus permitted to continue its inward swing a slight distance during the dwell in the motion of the slide 21 so that the end pair of transfer lingers 43, 44 will be allowed to pick up the cup C which is then in the pocket 26 of said slide. By means of this construction, it will be seen that arm 19 of the rocker lever 18 will leave the shoulder 20 of the feed slide during the dwell period.

It will thus be understood that when the feed slide 21 has moved to the position of Fig. 3, a dwell period in the cycle of the feed slide will occur, during which the end pair of transfer fingers 43, 44 will move downwardly and grasp a cup C from the pocket 26 in the end of the feed slide 21, and raise said cup out of said pocket. The end transfer fingers 43, 44 will then carry the cup C to the first drawing station. During the same period the previously drawn shells S will be moved to the next succeeding stations, with a substantially semi-circular motion by the respective pairs of transfer fingers 43, 44, carried in unison by the parallel swinging crossbar 42.

Modified form connected to a crank lever 59 rotatable on a stud 60,'

similar to the stud 17 of the first form. The stud 60 is rigidly attached to a bracket 61 by means of a nut 62, as in the first form.

While there have been disclosed in this speciiication two forms in which the invention may conveniently be embodied, it is to be understood that these forms are shown for the purpose of illustration only, and that the invention is not limited to the specific disclosures, but may be modified and 'embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired tosecure Letters Patent, is: f

l. In a multiple redraw press, a frame, a plurality of sets of cooperating stationary dies and reciprocating punches, mechanism to transfer blank cups successively from a vertical feed channel into alignment with the first punch and die set, comprising a horizontal outwardly spring-pressed feed slide having a pocket in the inner end of its upper side, a stud on said frame for limiting the inward movement of said feed slide, a reciprocating horizontal transfer cross-bar driven by a pair of crank arms and carrying a plurality of pairs of parallel cooperating depending resilient product-gripping fingers, means to repeatedly move said cross-bar and pairs of fingers as a unit in a substantially semi-circular arc in a single plane to transfer the products from station to station and means to reciprocate said feed slide comprising a Pitman link pivotally connected to the end of said cross-bar, a lever pivoted to said frame and pivotally connected at its upper end to said link and having at its lower end a lost motion connection with said feed slide whereby said slide will have a dwell period at the extreme end of its inward motion during which the end transfer fingers may pick up a blank cup from a pocket in said feed slide.

2. The invention as defined in claim 1, in which said Pitman link is connected to an extension of said crossbar at a point spaced from the shaft of the end crank arm.

References Cited inthe le of this patent UNITED STATES PATENTS 63,915 McIntire Apr. 16,1867 1,033,043 Wilcox July 16,1912 1,454,497 Walkup May 8,1923 1,604,220 Davis et al. Oct. 26, 1926 2,012,423 Ferris Aug. 27,1935 2,183,287 Candee Dec. 12, 1939 2,217,715 Swanstrom Oct. 15, 1940 

